Shetland favourite Alison O'Donnell reveals "Dark Tosh" storyline — and her partner's nervous reaction

There's much that will feel familiar about the latest season of Shetland – murder, shifty locals, brooding coastal landscapes – but leads Alison O'Donnell and Ashley Jensen have teased an unexpected "role reversal" between Tosh and Calder.

Season 10 sees the detectives investigating "the sinister murder of an elderly woman," reads the official synopsis.

"In the isolated hamlet of Lunniswick, the body of the retired social worker Eadie Tulloch has been out in the elements for a number of days. Suspecting the residents are holding back about their relationships with Eadie, Calder and Tosh begin to unravel a complicated web of lies.

"Worse still, there’s a personal link to the case for one of the team, testing loyalty to the limits."

Speaking to RadioTimes.com ahead of the new season’s release, O'Donnell said: "The pendulum swings a little bit. In this season, there are challenges that make both of our characters question themselves and each other, and they become slightly defensive about their actions.

"Tosh becomes more of the ball-breaker. As the season goes on, she stands up and says, 'Actually, this is the way it's going to be.' At the same time, we see a more compassionate side of Calder."

Jensen described that shift as "a little bit of a role reversal", with O'Donnell adding: "It's so lovely that the relationship and the characters are so established now that you can start to subvert things and see what happens. We get to see a caring side of Calder, because Tosh is dealing with something quite extreme, and her behaviour is quite… unlike anything we've seen before."

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"I was affectionately referring to her as 'Dark Tosh'," laughed O'Donnell. "There’s a particular sort of point—mostly around episode 5—where I was like, you know what, it's the 'Dark Tosh' journey.

"I've been really lucky to have had lots of great storylines, but this is a side of Tosh that I have never got to play, so that was really exciting. But I was also a wee bit nervous about it. I told my partner, I was like, 'This is the storyline.' And he was like, 'Oh, I’m worried about that, I don’t know...'

"But then I was like, we’re doing something right. You don’t ever want to rest on your laurels or for the show to become predictable. You want to keep pushing and exploring. And so I got over my nerves very quickly."

But O'Donnell was quick to point out that nothing happens on the show without context—there's always a reason behind the drama.

"The flaws are coming to the surface, but it’s just as true of the books as well, which obviously feeds into the characters in the show, and the roots that it's come from," she explained.

"You always get the humanity behind the actions—you kind of understand, well, that person is human and they're flawed and they're struggling. That was probably an error of judgement, but we get why it happened, and we make those mistakes in our own lives."

Jensen echoed that, adding that "you see them all as human beings that are a bit fallible—that kind of mess up a little bit, or say something they maybe ought not to, or do something, or push something a bit far, or behave in a certain way, or lose it a little bit.

"And I think that you’re seeing quite a lot of these characters out of their comfort zone."

O'Donnell and Jensen will once again be joined by series regulars Steven Robertson (DC Sandy Wilson), Lewis Howden (Sgt Billy McCabe), Anne Kidd (pathologist Cora McLean), Angus Miller (Donnie, Tosh’s partner), Conor McCarry (PC Alex Grant) and Eubha Akilade (PC Lorna Burns).

Samuel Anderson (Back to Black, Amandaland) has also joined the cast as Matt Blake, the new Procurator Fiscal.

Guest stars this season include Clive Russell (The Witcher), Ellie Haddington (Motherland), Niall MacGregor (The Bombing of Pan AM 103), Greg McHugh (Guilt), Frances Gray (Vera), Louise Brealey (Such Brave Girls), Stuart Townsend (Into The Deep) and Stephen McMillan (Toxic Town).

Shetland season 10 will start airing at 9pm on Wednesday 5th November on BBC One and BBC iPlayer. seasons 1-9 are available to stream on iPlayer now. Ann Cleeves's Shetland novels are available to buy.

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